Boeing Machinists are casting ballots Friday in a contract vote that could help set the course of future commercial aviation work in the Puget Sound area.

Approval of Boeing's contract offer, the company says, would ensure that the 777X, an update of the Everett-built 777, is built in the Puget Sound region. Rejection of the offer, according to Boeing, would likely send the $10 billion factory and its 8,500 direct jobs to another state — to be determined by a site selection process that Boeing already has launched.

About 31,000 members of the International Association of Machinists in the Puget Sound area — as well as in Wichita, Kan., and Portland, Ore. —are eligible to vote by absentee ballot and at their union halls from 5 a.m. to 6 p.m. The results are to be announced within a few hours after polls close.

Leaders of Seattle-based Machinists District Lodge 751 say that Boeing's proposed eight-year contract extension is full of "massive takeaways" and is barely improved from the proposal that members soundly rejected Nov. 13.